Vacuum interrupters enclosed in vacuum housings

ABSTRACT

A vacuum-type interrupter is enclosed within a vacuum environment, or housing to enable a better voltage-withstand between the live parts and the outer housing walls. Preferably, the outer housing is formed of metal, and is grounded, with terminal bushings extending through the grounded outer metallic housing. For other applications, however, when desired, the housing may, if desired, be of insulating material. In this latter event, the terminal leads require no conventional-type terminal-bushings for their accommodation. The operating mechanism may either be disposed externally of the outer housing, or the operating mechanism for the vacuum interrupter may be disposed internally of the outer housing.

' United States-Patent [191 Cherry et al.

[ VACUUM INTERRUPIERS ENCLOSED IN VACUUM HOUSINGS [75] Inventors: SidneyJ. Cherry, Elmira; Paul O. Wayland, Montour Falls, both of Ky. [73]Assignee: Westinghouse Electric Corporation,

' Pittsburgh, Pa, [22 Filed: July 21,1972

[21 Appl. No.1 273,885 g 52 us. ct; 200/144 B [SI] Int. Cl. Htllh 33/66[58] Field of Search 200/144 B [56] References Cited UNITED STATESPATENTS 1,720,413 7/1929 Greenwood ZOO/I44 B l,8(ll,736 4/1931 GreenwoodZOO/M4 B FOREIGN PATENTS OR APPLICATIONS 1.223.833 3/1971 Great Britain200/144 B i Lt L2 [451 June 4, 1974 Primary Examiner-Robert S MaconAttorney, Agent, or FirmW. R. Crout 7] ABSTRACT A vacuum-typeinterrupter is enclosed within a vacuum environment, or housing toenable a better voltage-withstand between the live parts and the outerhousing walls. Preferably, the outer housing is formed of metal, and isgrounded, with terminal bushings extending through'the grounded outermetallic housing. For other applications, however, when desired, thehousing may, if desired, be of insulating material. In this latterevent, the terminal leads require no conventional-type terminal-bushingsfor, their accommodation. a I

The operating mechanism may either be disposed externally of the outerhousing, or the operating mechanism for the vacuum I interrupter may bedisposed internally of the outer housing.

5 Claims, Drawing Figures LII/l/l/l/l/l/l/I/[ N -E VACUUM PATENTEDJUN4mm 8,814,881-

SHEEI 1 0F 3 PA'TENTEDJunmM, 8 88141881 ,suwaurs FIG.

VACUUM FIG.

, v 1. VACUUM INTERRUPTERS ENCLOSED IN VACUUM I-IOUSINGSCROSS-REFERENCES TO RELATED APPLICATIONS Reference may be made to UnitedStates patent application filed Oct. 30, 1970, Ser. No. 85,512 byRichard E. Kane and Frank L. Reese, entitled High- BACKGROUND OF THEINVENTION As well known by those skilled in the art, the disposition ofvacuum-interrupter elements within an oil casing has been recognized.See, for example, United States patent issued April 21, 1931 to TalmaGreenwood issued as U.S. Pat. No. 1,801,736. Also, reference may be madeto Greenwood US. Pat. No. 1,720,413, issued July 9,1929, also showing avacuum interrupter disposed interiorly within an oil tank, which isgrounded, and the operating mechanism being of an electrical nature,with the wires for the mechanism extending through the casing walls. 4

In United States patent application filed Oct. 30, 1970, Ser. No.85,512, by Richard E. Kane and Frank L. Reese, entitled High-VoltageCircuit-Interrupter Incorporating Series Vacuum-interrupter Elements,there is illustrated and described series vacuuminterrupter elementsdisposed within a gaseous environment, such as sulfur-hexafluoride (SFgas. In the aforesaid Kane arrangement, a generally ladder-likeoperating mechanism is provided to simultaneously effeet the opening andclosing movements of the plurality of movable contact elements disposedwithin the several series vacuum bottles".

SUMMARY OF THE INVENTION In accordance with the present invention, thereis proposed the "packaging of a vacuum interrupter within a vacuumenclosure, or casing, in place of having the vacuum interrupter bottle"disposed within air, gas (such as sulfur-hexafluoride (SF gas, forexample, or solid. insulation encapsulant. There results dispose one ormore vacuum-interrupter bottles" within an evacuated enclosure, and toeffect their operation bya mechanism, which may be disposed eitherwithin the evacuated enclosure, or externally thereof, as desired.

Another object of the present invention is the provision of an improvedvacuum-type circuit interrupter in which the vacuum-interrupterelements, either provided singly, or provided in multiple plural seriesarrangement, are disposed within an evacuated housing.

Still a further object of the present invention is to provide animproved tank-type circuit-interrupter with grounded metallic walls,having terminal-bushings extending therein, and providing one or morevacuum 2 bottles" disposed internally of the metallic grounded housing.

Further objects and advantages will readily become apparent upon readingthe following specification, taken in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. l is a vertical sectional viewtaken through a vacuum-type circuit interrupter embodying the principlesof the present invention, with the contact structure being illustratedin the closed-circuit position;

FIG. 2 is a fragmentary view of the circuit-interrupter of FIG. 1,illustrating a modification thereof, in which the operating mechanism iselectrical, and is disposed internally of' the evacuated metallichousing;

FIG. 3 is a second modification of the invention, in which three vacuumbottles" are disposed within an evacuated housing, each having its ownseparate mechanism for T tap switching purposes, the contact structurebeing illustrated in the closed-circuit position;

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, andmore particularly to FIG. 1 thereof, the reference numeral 1 generallydesignates a vacuum-type circuit interrupter. As shown in FIG. 1, itwill be noted that there is provided a pair of series-related vacuuminterrupter bottles 3, 4, each having its upper stationary contactterminal 3a or 4a connected to the lower end of a terminal bushing 6 or7 of rather conventional style. As well known by those skilled in theart, the terminal-bushings 6, 7 comprise a terminal-stud 8, extendinglongitudinally through an insulating body 9. Reference may be made toU.S. Pat. Nos. 3,222,625, 3,001,004 and 3,001,005 for the description ofsuch a type of terminal-bushing structure.

As shown in FIG. 1, each vacuum bottle 3, 4 generally comprises astationary contact 11, cooperable with a movable contact 13, the latterbeing actuated by a movable contact stem 15 extending through a bellowsl7, and actuated by an external cross-bar 19. The cross-bar 19 isactuated by a bridging member 21, to the intermediate portion 210 ofwhich is secured an operating rod 23, preferably formed of insulatingmaterial. The operating rod 23 extends through a bellows 25, and ismechanically connected to an external operating mechanism, indicated bythe reference numeral 27. During the opening and closing operations, aswill be obvious, the operating rod 23 is moved linearly in a verticaldirection, upwardly to close the breaker l, and downwardly to open thebreaker 11. This will, of course, effect simultaneous opening andclosing motions of the movable contacts 13 into and out of contactingengagement with the stationary contacts 11 in a manner well known bythoseskilled in the art.

The outer casing 29, which is preferably metallic and grounded, ismaintained in an evacuated condition, as by a vac-ion pump 31, or ifdesired, by a getter.

There are many advantages resulting from the aforesaid method ofenclosing the vacuum-interrupter bottles 3, 4. Some of these are thatthe vacuuminterrupter lengths, and spacings between the interrupters 3,4 are shorter, than those in air for two or more vacuum interrupters,which work in combination with one another. Additionally, the movableterminal temperatures are not critical, since oxidation will not takeplace in a vacuum. Since the outer chamber 29 and the mechanism 27 aregrounded, the structure is simpler and safer than conventional-typebreakers and switches. The concept permits putting two or more vacuuminterrupters 3, 4 in a vacuum to get high-voltage interruption, asillustrated in FIG. 1.

FIG. 2 illustrates a modification of the arrangement of FIG. 1 in whichthe operating mechanism 33 is of a solenoid type, and is providedinternally of the casing 29. It is electrical, and the wires forenergizing the same are indicated by the reference numerals 35 and 36.The

.solenoid 39 is energized and effects a downward motion of the solenoidplunger 40 into the winding 38, and

effects downward opening movement of the movable contacts 13. Upondeenergization of the solenoid 39, a spring 42 may effect a reclosure ofthe movable contacts 13 in an obvious manner.

With reference to FIGS. 3-5 of the drawings, it will be noted that inthis modification of the invention there is provided a T" tap-switchingarrangement 44, as diagrammatically illustrated in FIG. 5 of thedrawings. Three terminal bushings 46-48 extend through the outergrounded metallic housing 50, and the three vacuum bottles 52-54 aredisposed interiorly thereof, with each having its own separate operatingmechanism. The mechanisms are diagrammatically illustrated by thereference numerals 57-59. The operation of the vacuum bottles 52-54 willappear obvious in view of the previous description relevant to FIGS. 1and 2.

To effect a switching arrangement, it is merely necessary to actuate theparticular desired mechanism 57-59 to consequently effect closure of theselected vacuuminterrupter contacts 13 within the selected switch bottle52-54. Reference is again directed to the diagrammatic view of FIG. 5 inthis connection.

FIG. 4 illustrates more clearly how the vacuum bottles 52-54 andbushings 46-48 may be located in a desired arrangement with adequatespacing between the bOlllBS.

From the foregoing description it will be apparent that there has beenprovided an improved vacuum-type circuitinterrupter, in which the vacuumbottles" are disposed within an evacuated environment. Although certainof the modifications illustrate the casings to be grounded and of metal,the casing 29A, in the modification of FIGS. 6 and 7, is of insulatingmaterial, and there would then not be required a conventional-type ofterminal bushing.

There are many advantages to be obtained by the use of the foregoingarrangement.

1. Vacuum interrupter lengths and spacings between interrupters areshorter than those in air for two or more vacuum interrupters which workin combination with one another.

- 2. Movable terminal temperatures are not critical since oxidation willnot take place in vacuum.

3. Since the chamber and the mechanisms are grounded, the structure issimpler and safer than conventional breakers and switches.

... .-..QQ;1.sn P m t Pu t n 2 9 mallin a uum to get high voltageinterruption.

5. If the mechanism is incorporated into the vacuum chamber, the forcerequired to overcome the atmospheric pressure on the bellows iseliminated.

Although there has been illustrated and described specific structures,it is to be clearly understood that the same were merely for the purposeof illustration, and that changes and modifications may readily be madetherein by those skilled in the art without departing from the spiritand scope of the invention.

We claim as our invention:

1. A selecting switch for changing electrical connections comprising, incombination, a molded resinous insulating evacuated casing having aplurality of resinous-type insulating terminal bushings extending out ofthe upper cover portion thereof, a vacuum-interrupting unit supported atthe lower end of each of the plurality of resinous-type terminalbushings, each vacuum-type interrupting unit having a relativelystationary contact and a cooperable movable c'ontact making separablecontacting engagement within the evacuated enclosure, means electricallyconnecting the several movable contacts together, and a separateoperating mechanism for each vacuum-type interrupting unit forselectively operating the respective movable contact thereof accordingto the switching intentions of the operator.

2. The switch combination according to claim 1, wherein three insulatingterminal bushings are provided, and also three vacuum-type interruptingunits are disposed within the evacuated insulating resinous casing thusconstituting a T-tap selecting switch.

3. The combination according to claim I, wherein the operating means isof the solenoid type and disposed within the interior of the evacuatedresinous casmg. j

4. The combination according to claim 3, wherein a solenoid-coil isdisposed interiorly of the evacuated resinous casing, spring means areprovided to bias each respective movable contact to the closed-circuitposition, and electrical switching means are disposed externally of theevacuated resinous casing for operating the internally-locatedsolenoids.

5. The combination according'to claim 1, wherein the movable contact foreach of the vacuum-type interrupting units is actuated by asolenoid-type operating mechanism, the solenoid of which is disposedinteriorly within the evacuated resinous insulating casing.

1. A selecting switch for changing electrical connections comprising, incombination, a molded resinous insulating evacuated casing having aplurality of resinous-type insUlating terminal bushings extending out ofthe upper cover portion thereof, a vacuum-interrupting unit supported atthe lower end of each of the plurality of resinous-type terminalbushings, each vacuum-type interrupting unit having a relativelystationary contact and a cooperable movable contact making separablecontacting engagement within the evacuated enclosure, means electricallyconnecting the several movable contacts together, and a separateoperating mechanism for each vacuum-type interrupting unit forselectively operating the respective movable contact thereof accordingto the switching intentions of the operator.
 2. The switch combinationaccording to claim 1, wherein three insulating terminal bushings areprovided, and also three vacuum-type interrupting units are disposedwithin the evacuated insulating resinous casing thus constituting a''''T''''-tap selecting switch.
 3. The combination according to claim 1,wherein the operating means is of the solenoid type and disposed withinthe interior of the evacuated resinous casing.
 4. The combinationaccording to claim 3, wherein a solenoid-coil is disposed interiorly ofthe evacuated resinous casing, spring means are provided to bias eachrespective movable contact to the closed-circuit position, andelectrical switching means are disposed externally of the evacuatedresinous casing for operating the internally-located solenoids.
 5. Thecombination according to claim 1, wherein the movable contact for eachof the vacuum-type interrupting units is actuated by a solenoid-typeoperating mechanism, the solenoid of which is disposed interiorly withinthe evacuated resinous insulating casing.